Some wastewater treatment systems and methods use magnetically separable particles, e.g., magnetite, as a settling aid. See e.g., U.S. Pat. No. 6,099,738 to Wechsler et al. entitled “Method and System For Removing Solutes From a Fluid Using Magnetically Conditioned Coagulation”, and U.S. Publication No. 2008/0203015 entitled “System and Method For Enhancing An Activated Sludge Process”, both by the inventive entity hereof and incorporated by reference herein. As disclosed therein, magnetically separable particles, or magnetic ballast, such as magnetite, become enmeshed into the chemical and/or biological flocs. The magnetic ballast adds mass to the flocs which significantly increases their effective specific gravity and causes them to settle at a much faster rate in the clarifier. The result is the clarifier(s) of these systems functions at much higher surface overflow rate (SOR) and typically occupies a footprint which may be 10 to 20 times smaller than the clarifier of conventional wastewater treatment systems which do not utilize magnetically separable particles.
Such wastewater treatment systems and methods often need to monitor the level of the magnetic ballast in the moving slurry of the various components of the system, e.g., the aeration tank(s), the mixing tank(s), the weighting agent impregnation subsystem, various areas of one or more clarifiers, e.g., the sludge blanket, various lines and pipes of the system, and the like.
Conventional methods for determining the concentration of magnetic ballast in moving slurry of such systems typically include manually extracting a sample from the desired location in the system. The sample is then sent to a laboratory where a time consuming and cumbersome process is performed to determine the concentration of magnetic ballast in the moving slurry. Other conventional systems use a static cell which is cumbersome and difficult to use.
Thus, there is a need for a system and method which can automatically and continuously measure the concentration magnetic ballast in the moving slurry of a wastewater treatment system.